IPhone / TV obsession

Our son is now 16 years old and was diagnosed at a young age as "severely autistic". He is a very bright lad but has huge communication and sensory issues.

He has always had an obsession with TV but in recent times this has become a major problem specifically since I very stupidly showed him my new IPhone and some of it's clever features. His particular interest is obtaining screenshots of things that he likes which means that in the last 11 months he has built up a collection of over 70,000! He likes the beginning of programmes (particular CBeebies channel) and films and also the idents (bits inbetween). As this is mostly live he is always looking at the TV schedule and waiting for the next opportunity to obtain a screenshot.

The main problem with all of this is that there is a big chance that something is going to go wrong (internet goes down, hand slips from IPhone, forgot something was coming on etc) which means that he then becomes upset and physically aggressive to whoever is around. It has now got to the point where we dread going out because he is trying to screenshot whilst on a 3G connection in the car (recipe for disaster).

We feel that we need to get a grip on this situation as it's having a negative impact on all of our lives but it's rather different to previous obsessions such as Nintendo DS or video player because it's not something that you can put away and have a turn on later as this is mostly live TV so once the moment has passed you can't get back to it.

We don't feel that any of the ideas that we have come up with so far particularly work so we're looking for thoughts or suggestions from others. Feel free to comment as we are feeling a bit desperate!